The medial petal, called the labellum or lip (6), which is always modified and enlarged, is actually the upper medial petal; however, as the flower develops, the inferior ovary (7) or the pedicel usually rotates 180°, so that the labellum arrives at the lower part of the flower, thus becoming suitable to form a platform for pollinators. This characteristic, called resupination, occurs primitively in the family and is considered apomorphic, a derived characteristic all Orchidaceae share. The torsion of the ovary is very evident from the longitudinal section shown (below right). Some orchids have secondarily lost this resupination, e.g. Epidendrum secundum.

One of the most interesting things about growing any type of orchid is how they grow. Most of the houseplant orchids and even lady slipper orchids need good air flow around their roots. With indoor orchids, use an orchid potting mix that features some kind of blend of composted bark, expanded clay pellets, hardwood charcoal and peat moss or sand. The mix should create many air pockets for orchid roots to breathe.  

^ Guillaume Chomicki; Luc P.R. Bidel; Feng Ming; Mario Coiro; Xuan Zhang; Yaofeng Wang; Yves Baissac; Christian Jay-Allemand & Susanne S. Renner (2015). "The velamen protects photosynthetic orchid roots against UV‐B damage, and a large dated phylogeny implies multiple gains and losses of this function during the Cenozoic". New Phytologist. 205 (3): 1330–1341. doi:10.1111/nph.13106.
If you love watering plants, this type of orchid is for you, because it can tolerate a lot of dampness and regular watering. In fact, this orchid loves water so much that it can even tolerate wet feet. The petals consist of little pouch-like shapes surrounded by a moustache, and it comes in colors that include light green, white, and light burgundy.
Cymbidium carry tall stems with many flowers that have a more typical orchid shape. They are easily identified by their grassy leaves, and they readily form large clumps. Most common are the cool-flowering types, which need to experience a cooler winter (nights in the 40s for some time in the fall) in order to initiate flowering. Once the flowers open, they can last for up to two months or more, especially in a cool environment. These are very showy and rewarding plants, and a plant in a six-inch pot can carry three stems with 15 or more flowers each, depending on the type.
Orchids have many associations with symbolic values. For example, the orchid is the City Flower of Shaoxing, China. Cattleya mossiae is the national Venezuelan flower, while Cattleya trianae is the national flower of Colombia. Vanda 'Miss Joaquim' is the national flower of Singapore, Guarianthe skinneri is the national flower of Costa Rica and Rhyncholaelia digbyana is the national flower of Honduras.[29] Prosthechea cochleata is the national flower of Belize, where it is known as the black orchid.[30] Lycaste skinneri has a white variety (alba) that is the national flower of Guatemala, commonly known as Monja Blanca (White Nun). Panama's national flower is the Holy Ghost orchid (Peristeria elata), or 'the flor del Espiritu Santo'. Rhynchostylis retusa is the state flower of the Indian state of Assam where it is known as Kopou Phul.[31]
Once you develop more than a passing interest in orchids, you will quickly notice how diverse this exotic plant family is. Encompassing genera that yield both the vanilla you love to bake with and fragrances you love to wear, each flower has unique characteristics and care requirements. Compare your plants to some of the most commonly cultivated orchids to help you determine what type of orchid you are growing.